Air supply system for firefighting apparatus

ABSTRACT

A system for supplying compressed air and foam to produce a fire stream comprising an aerated foam is disclosed. The system includes an air compressor driven from a split shaft gear box of the type provided on fire trucks.

BACKGROUND AND SUMMARY OF THE INVENTION

This invention relates generally to an air supply system forfirefighting apparatus, and more particularly to a system for supplyingcompressed air and foam to produce a fire stream comprising an aeratedfoam.

Air supply systems of the above-indicated type are known and arereferred to in the art by the terms CAFS (compressed air foam system)and WEPS (water expansion pumping system). A typical system includes afoam injection system, a water pumping system and an air compressor.When employing mixture ratios of 1 cfm of air to 1 gpm of water, thesesystems can produce very desirable results in firefighting by the useand application of "Class A" foams to help achieve fire suppression andto deal with increased fire loads and related hazards.

It is the general object of the invention to provide an air supplysystem of the indicated type including means for driving an aircompressor using a split shaft gear box of the type commonly employed onfire trucks. More specifically, the air compressor is mounted on thehousing of the gear box in a manner so that a shaft extension of the aircompressor is contained in the gear box to be driven by a gear whichalso drives the fire pump that is also mounted on the fire truckadjacent the gear box.

In accordance with another object of the invention the drive for thecompressor is provided with a clutch which allows for the selective useof the compressor.

More specifically, the air supply system in accordance with theinvention comprises a rotary vane compressor mounted on the split shaftgear box of the midship pump provided on a fire truck. By thisarrangement, compressed air can be introduced into the water stream tomake an aerated foam, which foam is more effective as a fire stream thanplain water and penetrates faster.

Another feature of the air supply system in accordance with theinvention is that by introducing air into the fire hose, the actualweight of the hose is significantly reduced. Thus, it makes handling a21/2 inch fire hose become a one man job instead of requiring two orthree men to handle the hose.

Furthermore, the booster tank provided on the fire truck as a watersupply for immediate use at a fire scene can be used over a longer timeperiod since the water supply can be stretched. This makes the firetruck apparatus more effective in that the first fire truck to arrive ata fire scene can be used to apply a fire stream to the fire for a longertime period to limit the fire damage until a subsequent fire truck canbe hooked up to the hydrant and supply an additional fire stream.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a fragmentary sectional view of part of the transmission meansfor use in the air supply system in accordance with the invention.

FIG. 2 is a sectional view taken generally on line 2--2 of FIG. 1.

FIG. 3 is a sectional view taken generally on line 3--3 of FIG. 2.

FIG. 4 is a schematic view of an air supply system in accordance withthe invention.

.Iadd.FIG. 5 is a side view of a fire truck for incorporating the airsupply system in accordance with the invention. .Iaddend.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The main components of the air supply system of the invention are atransmission means 10, a fire pump 12, an air compressor 13 and a foamproportioner 15, which components are arranged in the manner shown inFIG. 4 to provide a compressed air foam system in accordance with theinvention.

The transmission means 10 comprises a split shaft gear box of the typeused on fire trucks as the transmission for driving the midship firepump provided thereon. Fire pump 12 is a midship pump of the type usedon fire trucks and may comprise, by way of example, a QG 150 midshippump manufactured by Hale Fire Pump Company. Fire pump 12 is a two-stagecentrifugal pump which operates to provide, by way of example, one totwo thousand GPM at 150 PSI and has impellers 14 and 16 mounted on arotating pump shaft 18 driven by a pump shaft drive gear 20 which ismounted within an upper housing portion 22 of the gear box 23 oftransmission means 10. The housing 19 of fire pump 12 is mounted on ahousing portion 22 of the gear box 23 of transmission means 10 to beadjacent thereto by suitable mounting bolts as is conventional..Iadd.The fire pump provides water to the fire stream at a desiredoperating pressure of multiple atmospheres and the operating pressure isat least about 100 to 150 psi. .Iaddend.

The transmission means 10 for driving the fire pump 12 is essentiallythe same as the transmission shown in U.S. Pat. No. 4,587,862 whichdiscloses a split shaft gear box of the type in use today on fire trucksfor driving fire pumps. Briefly, this type of pump transmission in usetoday comprises an input flange keyed to an input shaft, an outputflange keyed to an output shaft and a sliding gear which slides betweena "ROAD" position and a "PUMP" position. The input flange is connectedto the transmission on the fire truck engine to be driven thereby and tocause rotation of the input shaft keyed thereto. The output flange isconnected to the rear wheels of the fire truck for driving the same. Thesliding gear is slidable axially on a splined portion of the inputshaft. In the "ROAD" position of the sliding gear, its gear teeth areengaged with internally facing gear teeth formed in a collar that ispart of the output shaft.

In this manner, torque is transmitted from the input shaft to the outputshaft which has its output flange connected to the rear wheels of thefire truck for driving the same.

In the "PUMP" position of the sliding gear, its teeth are engaged withthe driving or intermediate gear which drives the pump, which is mountedadjacent to the pump transmission.

Referring to FIG. 3, transmission 10 comprises an input member 30 and anoutput member 32 rotatably mounted in axial end-to-end alignment in agear box lower housing 34 which is mounted below a gear box middlehousing 28 by means of suitable mounting bolts 36. The intermediate gear24 is rotatably mounted on housing 28 by bearing 26 contained therein.Input member 30 comprises an input flange portion 38 and a shaft portion40. Shaft portion 40 is rotatably mounted in housing 34 by means ofroller bearing means 42 contained in an opening 43 in housing 34 andenclosed by a cover 44. The portion of shaft portion 40 extending frombearing 42 into the interior of housing 34 is cylindrical and has anexternally formed involute splined portion 48.

Output member 32 comprises an output flange portion 50 and a shaftportion 52. Shaft portion 52 is rotatably mounted in housing 34 by meansof a pair of roller bearings 56 and 58 contained, respectively, withinan opening 59 in housing 34 and a cover 60 as shown in FIG. 3. Theportion of shaft portion 52 extending inwardly from bearing 58 into theinterior of housing 34 and to a location adjacent spline portion 48 iscylindrical and has an externally formed involute splined portion 62 ofthe same tooth configuration as the splined portion 48. The bearingsupports for the shaft portions 40 and 52 of input member 30 and outputmember 32 are constructed and arranged so that the splined portions 48and 62 are in axial alignment.

A sliding input gear 70 is mounted on splined portion 48 of input member30 and comprises an internal involute splined portion constructed sothat the sliding gear 70 is slidable axially on splined portion 48.Sliding gear 70 is provided with external teeth adapted to drivinglyengage the gear teeth of the intermediate gear 24. Sliding gear 70 isconstructed and arranged to cooperate with the splined portions 48 and62 of input member 30 and output member 32, respectively, to slidebetween a "ROAD" position wherein the internal splined portion ofsliding gear 70 is in engagement with both splined portions 48 and 62and a "PUMP" position wherein the internal splined portion of slidinggear 70 only engages the splined portion 48 of input member 30. In the"PUMP" position shown in solid lines in FIG. 2, the external gear teethof sliding gear 70 engages gear teeth of intermediate gear 24 forcausing rotation thereof whereby gear 24 drives the pump shaft 18through pump drive gear 20 to cause rotation of the pump impeller 16 andthe pumping of water through the fire pump 12. In the "ROAD" position ofsliding gear 70 the internal splined portion of gear 70 engages bothsplined portions 48 and 62 of input member 30 and output member 32,respectively.

As is conventional, there is also provided a "NEUTRAL" portion of thesliding gear 70 wherein the external gear teeth thereof are not indriving engagement with intermediate gear 24 and the internal splinedportion of sliding gear 70 is engaged with the splined portion of inputmember 30 only.

As is conventional, means are provided for actuating sliding gear 70between the "PUMP", "NEUTRAL" and "ROAD" positions thereof as describedabove. The actuating means comprises a gear shaft 80 mounted in openingsin housing 34 for sliding movement horizontally beneath sliding gear 70.An actuater arm 72 is carried on shaft 80 and extends upwardly therefromto engage sliding gear 70 in a recessed portion thereof. Suitable means,either manual or power operated, are engaged with shaft 80 to actuatethe same between the operating positions thereof as described above. Asthe shaft 80 is moved back and forth between these positions, a detentmechanism operates to frictionally secure the shaft 80 in the "PUMP"position and the "ROAD" position.

Air compressor 13 is preferably a sliding-vane-type rotary compressor ofa conventional construction comprising compressor shaft means includinga drive shaft portion 82A on which a compressor rotor is mounted, thecompressor rotor carrying radial vanes as is conventional insliding-vane-type compressor construction. By way of example, compressor13 is constructed to operate up to 500 cubic feet per minute .Iadd.andto deliver air at relatively high pressure of at least severalatmospheres to the water delivered to the fire stream.Iaddend.. For apurpose which will appear more fully hereafter, the compressor 13 ispreferably constructed of corrosion resistant material, i.e., resistantto the foam producing chemicals and water that is used in the system inaccordance with the invention. Thus, the compressor 13 may beconstructed of hardened stainless steel with end plates of a toughbronze for resistance to wear from the vanes and resistance to thecorrosion from the liquid and foam producing chemicals used in thesystem. Also, the compressor vanes are preferably of a low friction,strong plastic material.

Means are provided for mounting compressor 13 on the middle housing 28of the gear box 23 of transmission 10 means 10 on the side of gear box23 opposite to fire pump 12. Such means comprises suitable mountingbolts which mount the compressor 13 with its drive shaft portion 82Aarranged for access to the interior of the gear box 23 of thetransmission means 10 as shown in FIG. 1. Transmission means 10 isconstructed and arranged to drive the compressor shaft portion 82A bymeans of the intermediate gear 24 thereof which also drives the firepump 12 as discussed above. To this end, a compressor drive gear 84 iskeyed onto a compressor shaft portion 82B rotatably mounted within theinterior of the gear box housing 28 and constructed and arranged to bedriven by the intermediate gear 24. By this arrangement, as intermediategear 24 is caused to be rotated by the input gear 70 of the transmissionmeans 10, it functions to drive both the compressor drive gear 84 andthe pump shaft drive gear 20. The compressor drive gear 84 causes thecompressor shaft portions 82A and 82B to be rotated and this rotation istransmitted to the compressor rotor for operation of the compressor 13as is conventional in the art.

The drive for the compressor 13 includes a clutch means 90 which allowsselected use of the compressor 13 whereby the compressor 13 can beengaged only when air is needed for an operation such as the compressedair foam system of the invention. The clutch means 90 is shown in FIG. 1and is of a conventional mechanical clutch construction which can beoperated using either pressure air or vacuum. Also, the clutch means 90may be operated by a manual lever 88 which is provided for manualoperation under emergency conditions when the air supply control becomesinoperative. In the preferred embodiment of the invention, the clutchmeans 90 is operated by air pressure through a control line 89 which iscontrolled by a button-operated control valve (not shown) that directsair (such as from the air brake system of the fire truck) to one side ofa spring-biased clutch diaphram 91, the other side thereof being ventedat fitting 87. The diaphram 91 carries an actuator shaft 93 at itscentral portion, the actuator shaft 93 being mounted for axial movementwithin the interior of the compressor shaft portion 82B, which has ahollow construction to slidably receive said actuator shaft 93 as shownin FIG. 1. As discussed above, the compressor shaft means comprises afirst shaft portion 82A extending from the compressor housing andarranged to carry the compressor rotor and a second shaft portion 82Bwhich is mounted for rotation within the gear box housing in bearings 77and 79 and has the compressor drive gear 84 mounted thereon and keyedthereto for causing rotation thereof. Shaft portion 82A has a splinedexternal configuration adapted to be engaged with an internal splinedportion of a clutch plate 92 mounted thereon for axial slidable movementrelative thereto. Clutch plate 92 is carried on the right end (FIG. 1)of actuator shaft 93 at a bearing means 78 to be moved axially therebyand to rotate thereon. The clutch means 90 also comprises a rotatingdriving flange 94 which is keyed on the exterior of the compressor shaft82B for rotation therewith and is arranged to face the clutch plate 92for driving engagement thereby along the opposed cooperating faces ofclutch plate 92 and flange 94, as is conventional in this type of clutchconstruction.

When it is desired to operate the air compressor 3, the clutch means 90is engaged by the application of air pressure through the control line89 to thereby move the diaphram 91 to the left as shown in FIG. 1. Thismovement of the diaphram 91 causes a corresponding movement of theactuator shaft 93 and the clutch plate 92 engaged on the end thereof tothereby move the clutch plate 92 into engagement with the rotatingdriving flange 94 at their cooperating faces. The parts are shown in thedisengaged position in FIG. 1. In the engaged position, the rotation ofthe compressor drive gear 84 by the intermediate gear 24 causes rotationof the compressor drive shaft 82B and, by means of the engaged clutchplate 92 and flange 94, a corresponding rotation of the compressor shaftportion 82A whereby the compressor 13 is operated to cause rotation ofits rotor to discharge compressed air from its discharge as isconventional in the art.

When the air compressor 13 is not needed, the clutch means 90 isdecoupled by the removal of the air supplied through the line 89 wherebythe diaphram 91 returns to a disengaged position under the action of itsspring bias and moves to the right to the position shown in FIG. 1. Thismovement of the diaphram 91 causes a corresponding movement of theactuating shaft 93 and the clutch plate 92 engaged on the right endthereof to thereby disengage the clutch plate 92 from the rotatingdriving flange 94. Accordingly, the rotation of the compressor shaftportion 82B is no longer transmitted to the compressor shaft portion 82Aand the compressor 13 will no longer operate.

The above-described clutch-type of driving arrangement is conventionalin the art, and it will be apparent that various types of clutches maybe utilized to accomplish the above-described operation of thecompressor drive.

In FIG. 4 there is shown a compressed air foam system using an airsupply means in accordance with the invention. This system includes thetransmission means 10 which is driven from the engine 11 on the firetruck .Iadd.200 (FIG. 5) .Iaddend.and is arranged, as discussed above,to drive the fire pump 12 and the air compressor 13. The suction 100 ofthe fire pump is adapted to be connected to a water supply, such as ahydrant or a booster tank carried on the fire truck. The discharge 102of the fire pump 12 is delivered through a manifolded dischargeincluding a water delivery conduit 104 which is connected at itsdownstream end through a discharge valve 106 to a fire hose 108 whichhas a hose nozzle 110 at its downstream end for directing a fire streamonto the fire. The air compressor 13 has its suction 112 connected to afiltered air inlet 114. A conduit means 116 containing a control valve136 is provided for supplying a mixture of foam concentrate and water tothe suction 112 of the compressor 13. The means for supplying theliquid/foam mixture to the compressor suction 112 comprises the foamproportioner 15 which may be of a type disclosed in U.S. Pat. No.4,633,895. This type of foam proportioner is constructed and arrangedfor mixing a concentrated foam liquid solution with water in apredetermined proportion for use in a foam-water firefighting system.Conduit 104 contains a control valve 105 and the arrangement is suchthat when valve 105 is closed, a water supply line 115 directs the waterout of the water delivery conduit 104 and delivers it to theproportioner 15 which mixes said water at a predetermined proportionwith a foam concentrate and delivers the mixture to the suction 112 ofair compressor 13. The foam-like mixture delivered to air compressor 13helps in achieving a good edge and peripheral sealing as well as coolingand lubrication of he compressor vanes.

Foam proportioner 15 is supplied with the foam concentrate from a foamsupply tank 120 by way of a suitable piping connection 122. Varioussuitable foam concentrates are available in the art of use infirefighting applications, such as those available from MonsantoCorporation.

The discharge from the air compressor 13 is delivered through a conduitmeans 130 back to the water delivery conduit 104 at a locationdownstream of valve 105 and upstream of discharge valve 106. Thedirection of the flow through conduit 130 as described above iscontrolled by a check valve 131.

The system can be arranged to deliver water only to fire hose 108 byopening valve 105 and closing valve 136.

It will be apparent that various changes may be made in the constructionand arrangement of parts without departing from the scope of theinvention. For example, the transmission means may comprise a chain andsprocket drive means equivalent to the gear drive means disclosed.Accordingly, it is not desired to be limited except as required by thefollowing claims.

What is claimed is:
 1. An air supply system for firefighting apparatusincluding means for delivering a fire stream onto a fire, comprising:afire pump for delivering water under pressure to the fire stream, saidfire pump having a pump shaft means, a rotary vane compressor fordelivering air under pressure to the water delivered to the fire stream,said compressor having a compressor shaft means, a suction and adischarge, transmission means for driving both said pump and saidcompressor and including a gear box, means for mounting said pumpadjacent said gear box with said pump shaft means having a shaft portionrotatably mounted in said gear box, means for mounting said compressoradjacent said gear box with said compressor shaft means having a shaftportion rotatably mounted in said gear box, said transmission meanscomprising an input shaft rotatably mounted in said gear box, an inputgear mounted on said input shaft for rotation therewith, an intermediategear rotatably mounted in said gear box to be driven by said input gear,a pump drive gear for causing rotation of said pump shaft means, saidpump drive gear being mounted on said pump shaft portion to be driven bysaid intermediate gear, a compressor drive gear for causing rotation ofsaid compressor shaft means, said compressor drive gear being mounted onsaid compressor shaft portion to be driven by said intermediate gear,conduit means for connecting said compressor discharge to the firestream, and means for supplying a liquid foam to said compressorsuction.
 2. An air supply system according to claim 1 wherein said inputshaft is rotatably mounted in said gear box and includes a spline shaftportion; a cylindrical shaft portion and an input flange portion,andincluding an output member rotatably mounted in said gear box in axialalignment with said input shaft and including a spline shaft portion, acylindrical shaft portion and an output flange portion, said input gearcomprising a sliding gear slidably mounted on said spline shaft portionof said input shaft at an internal spline portion thereof and havingexternally facing gear teeth, said sliding gear being constructed andarranged to cooperate with said spline shaft portions of said inputshaft and said output member to slide between a road position whereinsaid internal spline portion thereof is in engagement with both thespline shaft portions of said input shaft and said output member and apump position wherein said internal spline portion thereof only engagesthe spline shaft portion of the input shaft, the gear teeth of saidsliding gear engaging the gear teeth of said intermediate gear in saidpump position of said sliding gear.
 3. An air supply system according toclaim 1 wherein said means for supplying liquid foam to said compressorsuction comprises a liquid proportioner, and including means forsupplying water from said fire pump to said proportioner, means forsupplying a foam chemical to said proportioner, and conduit means fordelivering a mixture of liquid and foam chemical from said proportionerto said compressor suction.
 4. An air supply system according to claim 1including clutch means for engaging and disengaging said compressorshaft means and said compressor drive gear.
 5. An air supply systemaccording to claim 4 wherein said clutch means is air operated andincludes diaphragm means responsive to air pressure.
 6. A compressed airand foam supply system for firefighting apparatus comprising:means fordelivering a fire stream onto a fire, a fire pump for delivering waterunder pressure to said fire stream delivery means and having a suctionand a discharge, conduit means for directing the discharge of said firepump to the upstream end of said fire stream delivery means, an aircompressor connected in said conduit means for discharging a fluid at afirefighting pressure and having an air inlet, a water foam suction anda discharge, and a foam proportioner for delivering a mixture of waterand a foam producing chemical to said water/foam suction of said aircompressor whereby the air compressor delivers a water/foam/air mixtureinto said conduit means.
 7. A system according to claim 6 wherein saidair compressor is a rotary vane compressor, said mixture being deliveredto said compressor to provide lubrication, sealing and cooling of thevanes thereof.
 8. A compressed air and foam supply system forfirefighting apparatus comprising:means for delivering a fire streamonto a fire, a fire pump for delivering water under pressure to saidfire stream delivery means and having a suction and a discharge, conduitmeans for directing the discharge of said fire pump to the upstream endof said fire stream delivery means, a rotary vane air compressorconnected in said conduit means for discharging a fluid at afirefighting pressure and having an air inlet, a liquid suction and adischarge, and means for delivering water from said conduit means tosaid liquid suction of said air compressor for the lubrication, sealingand cooling of the vanes of said compressor.
 9. An air supply system forfirefighting apparatus including means for delivering a fire stream ontoa fire, comprising:a fire pump for delivering water under pressure tothe fire stream, said fire pump having a pump shaft means, a compressorfor delivering compressed air at a relatively high pressure of at leastseveral atmospheres to the water delivered to the fire stream, saidcompressor having a compressor shaft means, transmission means fordriving both said pump and said compressor and including a casing means,means for mounting said pump directly on said casing means with saidpump shaft means having a shaft portion rotatably mounted in said casingmeans, means for mounting said compressor directly on said casing meanswith said compressor shaft means having a shaft portion rotatablymounted in said casing means, said transmission means comprising aninput shaft rotatably mounted in said casing means, an input drive meansmounted on said input shaft for rotation therewith, a pump drive meansfor causing rotation of said pump shaft means, said pump drive meansbeing constructed and arranged to drive said pump shaft portion and tobe driven by said input drive means, a compressor drive means forcausing rotation of said compressor shaft means, said compressor drivemeans being constructed and arranged to drive said compressor shaftportion and to be driven by said input drive means, and clutch means forengaging and disengaging said compressor shaft means and said compressordrive means for the selective use of said compressor.
 10. An air supplysystem according to claim 9 wherein said clutch means is air operatedand includes diaphragm means responsive to air pressure.
 11. An airsupply system according to claim 9 wherein said mounting means for saidcompressor is an integral part of said casing means.
 12. An air supplyaccording to claim 9 wherein said pump delivers water to the fire steamat a desired operating pressure of multiple atmospheres, said compressorbeing constructed and arranged to deliver air to the water delivered tothe fire stream at a pressure at least as high as said operatingpressure.
 13. An air supply system according to claim 12 wherein saidoperating pressure is at least about 100 to 150 psi.
 14. An air supplysystem according to claim 9 wherein said mounting means for said pump isan integral part of said casing means.
 15. An air supply systemaccording to claim 14 wherein said transmission means comprises a splitshaft gear box and said casing means includes a first housing portionfor containing said compressor and a second housing portion forcontaining said pump.
 16. An air supply system according to claim 15wherein said input drive means comprises an input gear, saidtransmission means includes an intermediate gear mounted to be driven bysaid input gear, said pump drive means comprises a pump drive gearmounted on said pump shaft portion to be driven by said intermediategear, and said compressor drive means comprises a compressor drive gearmounted on said compressor shaft portion to be driven by saidintermediate gear.
 17. An air supply system according to claim 16wherein said input shaft is rotatably mounted in said gear box andincludes a spline shaft portion, a cylindrical shaft portion and aninput flange portion,an including an output member rotatably mounted insaid gear box in axial alignment with said input shaft and including aspline shaft portion, a cylindrical shaft portion and an output flangeportion, said input gear comprising a sliding gear slidably mounted onsaid spline shaft portion of said input shaft at an internal splineportion thereof and having externally facing gear teeth, said slidinggear being constructed and arranged to cooperate with said spline shaftportions of said input shaft and said output member to slide between aroad position wherein said internal spline portion thereof is inengagement with both the spline shaft portions of said input shaft andsaid output member and a pump position wherein said internal splineportion thereof only engages the spline shaft portion of the inputshaft, the gear teeth of said sliding gear engaging the gear teeth ofsaid intermediate gear in said pump position of said sliding gear..Iadd.
 18. An air supply system for firefighting apparatus includingmeans for delivering a fire stream onto a fire, comprising:a fire pumpfor delivering water under pressure to a fire stream, said fire pumphaving a pump shaft means and a pump outlet, a first conduit having afirst end and connected to said pump outlet and a second end providedwith a nozzle for delivering said fire stream onto a fire, a compressorfor delivering compressed air and foam at a relatively high pressure ofat least several atmospheres to the water delivered to the fire stream,said compressor having a compressor shaft means and a compressor outlet,a second conduit having a first end connected to said compressor outletand a second end connected to a connection portion of said first conduitfor injecting said compressed air into said first conduit so that thewater downstream of said connection portion has a higher air contentthan fluid upstream of said connection portion, transmission means fordriving both said pump and said compressor and including a casing means,means for mounting said pump directly on said casing means with saidpump shaft means having a shaft portion rotatably mounted in said casingmeans, means for mounting said compressor directly on said casing meanswith said compressor shaft means having a shaft portion rotatablemounted in said casing means, said transmission means comprising, aninput shaft rotatable mounted in said casing means, an input drive meansmounted on said input shaft for rotation therewith. a pump drive meansfor causing rotation of said pump shaft means, said pump drive meansbeing constructed and arranged to drive said pump shaft portion and tobe driven by said input drive means, a compressor drive means forcausing rotation of said compressor shaft means, said compressor drivemeans being constructed and arranged to drive said compressor shaftportion and to be driven by said input drive means, and clutch means forengaging and disengaging said compressor shaft means and said compressordrive means for the selective use of said compressor. .Iaddend..Iadd.19. The air supply system of claim 18 in which the water in said firstconduit upstream of said connection portion has an operating pressure ofat least about 100 to 150 psi. .Iaddend..Iadd.20. The air supply systemof claim 19, in which said fire pump operates at about 1000-2000 GPM andsaid compressor operates at a pressure equal to or in excess of thewater pressure. .Iaddend..Iadd.21. The air supply system of claim 18 inwhich said input drive means simultaneously drives both said pump drivemeans and said compressor drive means and drives said compressor at ahigher RPM than said pump drive means. .Iaddend..Iadd.22. The air supplysystem of claim 21 in which said compressor drive means is alwaysrotating when said pump drive means is rotating and said clutch means isselectively operable to engage or disengage said compressor drive meansfrom said compressor shaft means. .Iaddend..Iadd.23. An air supplysystem and firetruck combination including means for delivering a firestream onto a fire, comprising:an engine mounted in a firetruck fordriving said firetruck, a fire pump mounted in said firetruck fordelivering water under pressure to a fire stream, said fire pump havinga pump shaft means, a compressor mounted in said firetruck fordelivering compressed air and foam at a relatively high pressure of atleast several atmospheres to the water delivered to the fire stream,said compressor having a compressor shaft means, transmission meansmounted in said firetruck for driving both said pump and said compressorand including a casing means, means for mounting said pump directly onsaid casing means with said pump shaft means having a shaft portionrotatably mounted in said casing means, means for mounting saidcompressor directly on said casing means with said compressor shaftmeans having a shaft portion rotatably mounted in said casing means,said transmission means comprising, an input shaft rotatable mounted insaid casing means and connected to said engine, an input drive meansmounted on said input shaft for rotation therewith, a pump drive meansfor causing rotation of said pump shaft means, said pump drive meansbeing constructed and arranged to drive said pump shaft portion and tobe driven by said input drive means, a compressor drive means forcausing rotation of said compressor shaft means, said compressor drivemeans being constructed and arranged to drive said compressor shaftportion and to be driven by said input drive means, and clutch means forengaging and disengaging said compressor shaft means and said compressordrive means for the selective use of said compressor. .Iaddend..Iadd.24.The combination of claim 23 in which said input drive meanssimultaneously drives both said pump drive means and said compressordrive means and drives said compressor drive means at a higher RPM thansaid pump drive means. .Iaddend..Iadd.25. The combination of claim 24 inwhich said compressor drive means is always rotating when said pumpdrive means is rotating and said clutch means is selectively operable toengage or disengage said compressor drive means from said compressorshaft means. .Iaddend.